A sheet processing apparatus is known which makes a reinforce roller to be moved to a home position and displays an indication to urge jam processing on a display means in case that some sort of abnormality is sensed and a reinforcing operation is halted during the reinforcing operation in a saddle unit having a reinforcing unit.
However, even if the reinforcing operation halts, the jam processing is not necessarily required. In case that the reinforcing operation halts with the load generated by thick sheets, it is only necessary to perform the reinforcing operation again without performing the jam processing. That is, every time the reinforcing operation halts, to display an error indication for urging the jam processing and to make a user confirm the indication may urge the user to do an unnecessary work and thereby may be a burden to the user.